Electrical connector for resilient structures



M. B. LUKE Aug. 18, 1953 Filed Mar ch 1, 1950 Patented Aug. 18, 195 3 ELECTRICAL CONNECTOR FOR RESILIENT STRUCTURES Marvin B. Luke, Akron, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application March 1, 1950,.Serial No. 147,032

13 Claims. (01. ,244--134) This invention relates to electricalconnectors, especially connectors for resilient structures, and is useful especially in electrically heated, thin sectional coverings for aircraft and other .Surfaces.

Prior propeller blade coverings or shoes utilizing a unitary electrical heating element for the whole shoe have sometimes required replacement and discarding because .the outer portion of .the shoe toward the faster-traveling tip of the blade has become objectionably abraded or otherwise damaged thereby resulting in failure of the outer portion before the inner portion of the shoe at the slower-traveling root of the blade has shown signs of substantial wear. The replacement and discarding of the whole shoe has involved substantial expense.

An object of the invention is to provide for overcoming the foregoing and other difficulties and disadvantages of the prior constructions.

Other objects are to provide an improved plug and socket connector and especially one in which contact is maintained by the action of an elastic body; to provide for maintaining in an improved manner a contacting engagement between the plug and socket; to provide for urging the contactor of the socket resiliently toward the plug element by virtue of stress in an elastic body exteriorly of the socket; to provide for thinness and sturdiness of construction of the socket and the plug; to provide for mounting the socket in a thin elastic body without objectionable increase in the overall thickness of the body; to provide for separability of the socket and plug connector structure including the elastic body associated with the socket; and to provide for simplicity of construction, convenience oimanufacture and for effectiveness of operation of the socket and plug.

Further objects areto provide for-electrically connecting separablesections of an electrically heated, protective covering; toprovide for utilizing elastic material of the covering to maintain an eiiective electrical connection between the sections; to provide for replacementof a section of the covering together with electrical conprovide for electricallyinterconnecting thessections at their adjoining end faces. I

These and other objectsand advantages of the invention will be apparent from the'following description, reference being madeto the accompanying drawings which form apart of this specification.

,Fig. 1 is a front elevational view showing electrically/heated sectional shoes constructed in accordance with and embodying the invention and 2 mounted on a multi-bladed propeller, parts .being broken away,

Fig. 2 is a perspective view of an outer section of a shoe including plug elements at its inner end ;face, broken lines indicating a blade supporting the section, parts being broken away,

Fig. 3 is a plan view of a sectional shoe before mounting on the blade,

Fig. ,4 is a plan view in an enlarged scale of the adjoining margins of the sections shown in Fig. 3, including the connectors, parts being broken way.

Fig. 5 is an exploded view in perspective of elements constituting the electrical socket, parts beinggbroken away,

Fig. 6 is aperspective view of the socket in assembled condition engaging a plug element and connected to a conductor, parts being broken away and in section, and

Fig. 7 is a sectional viewtaken along line 1'i of Fig. 4.

The construction shown in the drawings comprises electrically heated, sectional coverings or shoes iii, 1 I, ll? of elastic material for protecting the leading edges of blades it, it, it of an aircraft propeller it against the accumulation of ice. Since the shoes are substantially alike, only the construction of the shoe is will be be described in detail.

The sectional shoe it] is relatively thin as compared to its Width and to the thickness of the blade l5, and has separable heating sections it and IQ for mounting along the blade with margins 29 and 2! of the sections adjoining one another, as shown especially in Fig. 1. Each heating section, for example the inner or root section 18, has a thin body of elastic material '22, preferably resilient rubber material which -may be a natural rubber or a synthetic rubber or so-called man-made rubber. Stretchable or substantially non-stretchable reinforcing fabric 23,123 such, for example, as square-woven fabric otcottomnylon, glass or other suitable filamentary material may be imbedded in the rubber bodyr22 including its rearward, tapered marginal portions 16a and itb and adjacent its upper and lowerfaces, as shown especially in Fig. -'l. The outersection I9 is desirably of increased thickness along its immediate leading edge region to provide anarrowprojection l9a for increased resistance to abrasion from air-borne particles. 'The invention provides at the margins 20 and 2| separableconnecting means capable of mainprongs zfi -and 27 at the margin 2| of the other or-outer section i 9 for separable engagement with 3 the sockets. Since the sockets and plug elements, respectively, are substantially alike except as to a right and a left hand arrangement thereof, only the construction of the socket 24 and the plug element 28 will be described in detail.

The socket 24, which has a thickness not exceeding that of the rubber body of the section It, has a pair of elongated plates 28, 29 of electrically conductive thin sheet metal which may be a brass or other copper alloy, secured to one another in overlying, spaced-apart, substantially parallel relation, as shown especially in Fig. 6, as by attaching lugs 36, 3|! and 3|, 3|. The attaching lugs may be spaced-apart portions of the lower plate 253 at each end thereof upwardly and inwardly bent, as shown by broken lines in Fig. 5, to engage reduced end extensions 32 and 33, respectively, of the upper plate 28.

A pair of contact elements or contactors 34, 35 of suitable conductive metal material, desirably H-shaped in plan, are disposed spaced-apart between the plates in the direction of the ends thereof. The contactors are in slidable, contacting relation to the plates and provide with the plates a recess at 38 between them for reception of the plug element of suitable conductive metal material in contacting engagement with the contact elements. The H-shaped contactors 3 have guide portions 3?, 38 which interconnect the legs of the H, extending slidably between the pairs of attaching lugs 39, 39 and 3|, 3|, respectively, to guide the sliding movement of the contactors relative to one another. The H- shaped contactors have their adjacent inner legs disposed inwardly of the lugs to engage the plug and their outer legs 39, W disposed outwardly of the lugs for disposition in the rubber material of the section 13, the spacing between the legs of each contactor permitting sliding movement of the contactor to a determinate extent for engaging and disengaging the plug.

The socket 24, by virtue of its compact, thin construction, may be imbedded in the rubber material of the margin 20 intermediate the thickness thereof without objectionable thickening or localized bulging of the margin, as shown especially in Fig. 7. The outer legs 39, 40 of the contactors 3d, 35 are bonded to the rubber material beyond the attached ends of the plates 28, 29, whereby sliding movement of the contactors is resisted resiliently and the contacting engagement with the plug 25 is maintained by the resilient action of the rubber material under pressure of the engaged contactors.

end of the inner section and 52 at the outer end The socket Ed in the imbedded condition is positioned adjacent an end face 4| of the margin 2!! with the recess at 35 in communication with the end face 4|. This facilitates insertion of the plug element 26 which is imbedded in the rubber material of the adjacent margin 2| of the section l9 intermediate the thickness thereof and projects from an end face '32 of the margin 2| toward the socket 24.

The socket 24 may be connected to electrical heating means 43 of the section l8 as by a soldered connection at at joining the connecting extension 32 of the upper plate 28 with a conductor 45, desirably of flexible, braided wire construction, of the heating means 43. The plug 26 at its imbedded end portion may be connected to electrical heating means 45 of the other section l9 as by a soldered joint connection at M with a suitable flexible conductor 48 of the heating means 46.

The other socket 25 may be connected substantially like the socket M to a suitable second of the outer section are provided to complete the electrical circuits of the sections.

Each heating means 43, 46 may be of any suitable resistance elements such as resistance wires or electrically conductive rubber.

The sectional shoe It] may be molded in fiattened condition as shown in Fig. 3, and independently and adhesively attached to the blade l5 substantially symmetrically about its leading edge H, a suitable rubber cement of the air-curing type being utilized for the attachment.

The initial mounting of the sectional shoe H! on the blade l5 may be accomplished by first positioning the inner section H3 at the root of the blade after which the adjoining outer section I9 is mounted in place. The outer section i9 may be first adhered to the leading edge along a narrow zone at the projection lea, the plug elements 25 and 27 then being inserted into the sockets 2 1, 25 in contacting engagement with the contactors of the sockets, after which the remainder of the outer section including the rearward marginal portions Ida, 59b is adhesively attached to the blade. The conductors d5, 49 of the inner section It may then be connected to the source of heating current, and by virtue of the socket and plug connections between the inner and outer sections l8, I9, respectively, the mounted shoe is in condition to provide temperatures at each section effective to prevent the accumulation of ice on the shoe. The mounted shoe presents a smooth, aerodynamic outer surface to the ambient air for minimizing propeller losses.

Effective electrical contacting engagement between the sockets 24, 2E and the plug elements 25, 2'. is maintained despite vibratory and other movements of the blade under rotation of the propeller tending to loosen or break the connec tions; because the stressed rubber material of the shoe connected with the contactors resiliently urges each pair of contactors continuously toward the engaging plug element, while the rubber material absorbs and accommodates the vibratory and other movements without substantial lessening of the urging action of the contactors.

Also, the rubber material of the shoe accommodates not only some misalignment of the plug elements relative to the sockets, but in addition. facilitates such movement of the plug elements as may be required for their insertion into the sockets during the mounting of the outer section id. The rubber material of the section l9 facilitates maintaining the plug elements in good electrical contact with the contactors by resiliently resisting movement of the plug elements longitudinally and laterally of the recesses at 36, 36 of the sockets, especially under rotation of the propeller.

Whenever it is desired to replace a heating section such, for example, as the outer section |9 of the shoe, the outer section may be removed outer end first from the blade and the plug elements disengaged from the sockets, thereby permitting "the adhesive attachment of a replacement outer section to the blade and the connection of such replacement section to the original inner section,

as described hereinabove; thus restoring the iceremoval effectiveness of the sectional shoe H] as a whole with minimum expense to the owner of the aircraft.

Variations may be made without departing from the scope of the invention as it is defined in the following claims.

I claim:

l. A sectional protective covering relatively thin as compared to the width thereof and comprising separable sections of elastic material for mounting along and in conformance with the leading edge of an airfoil with margins of said sections adjoining one another and comprising elastic material, and electrical heating means in said sections including separable connecting means at said margins comprising a socket at the margin of one section and a plug element at the margin of the other section, said socket comprising a substantially flat plate secured to said elastic material of the covering section, a contactor slidable on said plate, and an element providing with said plate and said contactor a recess between them for reception of said plug element in engagement with said contactor, said contactor being connected with said elastic material of the covering section to resist resiliently and solely by the elastic action of said material movement of said contactor under pressure of said plug element and maintain the contacting engagement.

2. A sectional protective covering relatively thin as compared to the width thereof and comprising separable sections of resilient rubber material for mounting along and in conformance with the leading edge of an airfoil with margins of said sections adjoining onev another and comprising resilient rubber material, and electrical heating means in said sections including separable connecting means at said margins comprising a socket at the margin of one section and a plug element at the margin of the other section, said socket comprising a pair of plates secured to one another in overlying spaced-apart relation and secured to said margin of the covering section, and a pair of spaced-apart conta-ctors between said plates in slidable relation thereto and providing with said plates a recess between them for reception of said plug element in engagement with said contactors, said contactors each being connected with said rubber material of th covering section to resist resiliently and solely by the resilient action of said material movement of said contactors under pressure of said plug element and maintain the contacting engagement.

3. A sectional protective covering relatively thin as compared to the width thereof and comprising separable sections of resilient rubber material for mounting along andin conformance with the leading edge of an airfoil with margins of said sections adjoining one another and comprising resilient rubber material, and electrical heating means in said sections including separable connecting means at said margins comprising a pair of sockets imbedded in the rubber material of the margin of one section and spacedapart laterally of the section and a pair of plug elements imbedded in the rubber material of the margin of the. other section and projecting from the end face of the. margin toward said sockets at positions laterally spaced-apart in alignment with said sockets, each of said sockets having a thickness not exceeding that of the margin and comprising a pair of plates secured to one another in overlying spaced-apart relation and a pair of spaced-apart conta-ctors between said plates in slidable relation thereto and providing with said plates a recess between them in communication with the end face of the margin for reception of a plug element in engagement with said contactors, said contactors each being connected with said rubber material of the covering section to resist resiliently and solely by the resilient action of said material movement of said contactors under pressure of the plug element and maintain the contacting engagement.

4. An electrical connector comprising a body including elastic material, a second body presenting a face for disposition adjoining the first said body, and electrically-operated means associated with each of the bodies including separable connecting means comprising a socket on the first said body and a plug element at said face of said second body and projecting therefrom toward said socket, said socket comprising a pair of plates secured to one another in overlying spaced-apart relation and secured to the first said body and contactor means between said plates for receiving and engaging said plug element, said contactor means including a contact element moveable between said plates in slidable relation thereto upon engagement by said plug element and connected with said elastic material of said first said body to resist such movement resiliently and solely by the elastic action of said material and maintain the contacting engagement.

5. An lectrical connector comprising a body of resilient rubber material, a socket on said body, and a plug including a prong, said socket comprising a plate of substantially flat configuration secured to said rubber material of said body, a contactor of substantially flat configuration slidable on said plate in face-to-face relation thereto, and an element providing with said plate and said contactor a recess between them for reception of said prong in engagement with said contactor, said contactor being connected with said material of said body to resist sliding movement resiliently and solely by the resilient action of said material and maintain the contacting engagement under pressure of said prong.

6 An electrical connector comprising a thin body of resilient rubber material, socket in said body having a thickness not exceeding that of said body, a plug including a prong, said socket comprisinga pair of plates secured to one another in overlying spaced-apart relation and disposed intermediate the thickness of said body in secured relation thereto, a pair of spaced-apart contactors between said plates in slidable relation thereto and providing with said plates a recess between them for reception of said prong in engagement with said contactors, said contactors being connected with said rubber material of said. body to resist sliding movement resiliently by the resilient action of said material and maintain the contacting engagement under pressure of said prong.

'Z. An electrical connector comprising a substantially flat plate, a substantially fiat contactor slidable on said plate in face-to-face relation thereto, an element mounted on said plate providing with said plate and said contactor a recess between them for reception of a plug element in engagement with said contactor, and a body of resilient rubber connected with said contactor 7 to resist sliding movement of the latter solely by the resilient action of said rubber under pressure of said plugelement.

8. An electrical connector comprising a pair of plates secured to one another in overlying spaced-apart relation, a pair of spaced-apart contactors between said plates in slidable relation thereto and providing With said plates a recess between them for reception of a plug element in engagement with said contactors, and a body of resilient rubber connected with each of said contactors to resist movement of the latter under pressure of said plug element.

9. An electrical connector for insertion in a body of resilient rubber, said connector comprising a plate of substantially flat configuration and stiff metal material, a contactor of substantially fiat configuration and stiff metal material slidable on said plate in face-to-face relation thereto, and an element mounted on said plate providing with said plate and said contactor a recess between them for reception of a plug element in engagement with said contactor, said contactor including means for connection to said rubber of said body to resist sliding movement of said contactor resiliently and solely by the resilient action of said rubber under pressure of said plug element and maintain, the contacting engagement.

10. An electrical connector for insertion in a body of resilient rubber, said connector comprising a pair of plates of substantially fiat metal material secured to one another in overlying spaced-apart substantially parallel relation, a

pair of spaced-apart contactors of said metal so material between said plates in slidable relation thereto and providing with said plates a recess between them for reception of a plug element in engagement with said contactors, said contactors including means for connection to said rubber of said body to resist sliding movement of said contactors resiliently by the resilient action of said rubber under pressure of said plug element and maintain the contacting engagement.

11. An electrical connector for insertion in a thin body of resilient rubber, said connector having a thickness not exceeding that of said body and comprising a pair of elongated plates of fiat plates in slidable relation thereto and providing with said plates a recess between them for reception of a plug element in engagement with said contactors, each of said contactors including an extension thereof of said metal material extending between the spaced-apart attaching means at an end of said plates and extending beyond the end for connection to said rubber of said body to resist sliding movement of said contactors resiliently by the resilient action of said rubber under pressure of said plug element and maintain the contacting engagement.

12. An elongated sectional protective covering for the leading edge of an airfoil exposed to ,fiow of air under icing conditions, said covering comprising resilient rubber of sheet-like form and relatively thin as compared to its Width having separable sections for mounting along the leading edge of an airfoil with an inner surface of each sectionagainst the airfoil and a substantially smooth outer surface of each section exposed to the flow of air and with margins of said sections extending laterally of the covering having end faces adjoining one another and comprising said resilient rubber, and electrical heating means in said sections beneath the outer surfaces thereof for preventin the accumulation of ice on such outer surfaces, said heating means including separable connecting means at said margins comprising a pair of sockets imbedded in said rubber of the margin of one section beneath the outer surface thereof and spaced-apart laterally of the covering and a pair of plug elements imbedded in said rubber of the margin of the other section beneath the outer surface thereof and projecting from the end face of the margin'toward said sockets at positions laterally spaced-apart in alignment with said sockets, each of said sockets having a thickness less than that of the margin of the first said section and comprising a pair of substantially flat plates secured one to the other in overlying spaced-apart parallel relation and a pair of spaced-apart substantially flat contactors extending in the direction alongthe margin and between said plates in slidable relation thereto providing with said plates a recess between them in communication with the end face of the margin for receiving a plug element in engagement with said contactors, said pair of contactors each being connected with said resilient rubber of the covering section to resist resiliently and solely by the resilient action of said resilient rubber sliding movement of said contactors under pressure of the plug element and maintain the contacting engagement.

13. An electrically heated sectional protective covering comprising separable sections of elastic material in sheet-like form each relatively thin as compared to its width for disposition conformingly upon a surface to be protected with margins of said sections adjoining one another and comprising elastic material, and electrical heating means in said sections including separable connecting means at said margins comprising a socket in the margin of one section having a thickness not exceeding that of said one section and a plug element in the margin of the other section, said socket comprising an elongate generally flat plate extending in the direction along said margin of said one section and imbedded in and bonded to the elastic material of such margin intermediate the thickness thereof, a generally fiatcontact element slidably mounted on said plate at a face thereof for movement in said direction in the plane of the covering, and an element carried by said plate at said face thereof to provide with said plate and said contact element a recess between them for receiving said plug element in engagement with said contact element, said contact element having a portion thereof bonded to said elastic material of said one section to resist resiliently and solely by the elastic action of such elastic material, sliding movement of said contact element under pressure of said plug element and to maintain the contacting engagement.

MARVIN B. LUKE.

References Cited in the file of this patent UNITED STATES PATENTS 

